Add 'WorkerGlobalScope::isSecureContext'

third_party/WebKit/Source/core/workers/WorkerGlobalScope.idl

Index: third_party/WebKit/Source/core/workers/WorkerGlobalScope.idl
diff --git a/third_party/WebKit/Source/core/workers/WorkerGlobalScope.idl b/third_party/WebKit/Source/core/workers/WorkerGlobalScope.idl
index 811d8baf7c18010ea4a50de89de8675ba45f2294..116145c46c86f681c14d4e21bdb4b678ae7bd559 100644
--- a/third_party/WebKit/Source/core/workers/WorkerGlobalScope.idl
+++ b/third_party/WebKit/Source/core/workers/WorkerGlobalScope.idl
@@ -44,6 +44,7 @@
     [RaisesException] void importScripts(DOMString... urls);
     readonly attribute WorkerNavigator navigator;
 
+
     // Console API
     // https://console.spec.whatwg.org/#console-interface
     // [Replaceable] readonly attribute Console console;
@@ -57,6 +58,10 @@
     // Unhandled Promise Rejection Events
     attribute EventHandler onrejectionhandled;
     attribute EventHandler onunhandledrejection;
+
+    // Secure Contexts
+    // https://w3c.github.io/webappsec-secure-contexts/#dom-windoworworkerglobalscope-issecurecontext
+    [ImplementedAs=isSecureContextForBindings] readonly attribute boolean isSecureContext;
 };
 
 WorkerGlobalScope implements WindowBase64;